Mechano-pneumatic cushion for power presses



J. C. HAN NA June 24, 1930.

MECHANO PNEUMATIC CUSHION FOR POWER PRESSES Filed Dec. 1928 Int/677%"- J'hn C-Hanna Patented June 24, 1930 7 JOHN o. HANNA, or oHIo Ae-o, LLI OIS, AssreNon To HANNA ENGINEERING w'onKs-L q r oronron'eo,animus/n CORPORATION onsi nrnols MECHANOQffiEIlMATIC ousnron FOR rownn rnn ssns Jainism knaiicer b r 3,1928 seen Nme'eaees.

'lhis invention relateslto die presses or drawing presses which maybe used for em e. .cei ng, i h l qwiI e neIet -Ls Q; In tl epqm o form of die press ;there is 1 311K131??? platen carrying the upper die which is iven 7 a: uniforinup andfdovvn fstroke by a prank andfly' Wheel and 'presses the matem1 upon a fi 'redjlovver plat-en supporting I the lower die, Thereis usually'some form iadjustingmeans for varying the approach ofthe'upper die tothelower 'die L 'j 'FOr if the upper platen is given a uniforni stroke and if the thickness of the'material inserted in thepress variesthere tvill bea corresponding variationin iiiaximilrrrpresstire exerted upon theinaterial, therefore, it iso'ustornaryto change the normal relation between the upper platen and lower" platen in 'aecordanee With the thipliness "of the material inserted 20 in the press] Butifthe thiolrnesso fthe Inate1 'ial"oontinually varies, it is objectionable to meohanieally adjust the ,press each time, therefore; itis proposed 'i'nt his invention to 1 provide a lower platen, having supporting" means consisting of yieldahlea-nd adjustable means resisting movement of the lower platen until the desired pressure'on the ma terial has been reached. Thus asthe'upper platen moves topress the materialthe lower 30 platen remains stationary until the f1naximum desired pressure is reached and then moves to prevent an increased pressure; 4 It is further anobjeotofthis invention to provide fluid pressure constituting the 'eushioning support for the lovver platen, preferably the fluid used is air.'.'- I

It is further an object of this invention to so support the lower'plat'en that erelatively low airpressure may act throughm'eohanieal leverage action to develop; an inereased re sistance to the movement of the lower platen, .An additional object of the invention is to provide simple andcoinpact leverage means that'vvill cause a uniform pressure tobe distributed over thelOWersurfaee of the platen by causing the resisting, means toact at a plurality of spaced points. j I

Another additional Oh'eet of this-invention to provide a transverse "element eoting through inclined surfaees to resist moveinent of the lower platen, and" having rolling elements between {the inclined surfeeesto reduce the friction.

Additional objeetsand advantages vvill clearly be apparen as the description procee'ds; 4 I

In the drawings a single figurefshovvs the side elevation of the press, partially i-nsection. I I I I a The figure sl'iovvs'an ordinarycrank-and fly-Wheel press hutit ivlllbeapparent that the iniprcwement' 'inay be adapted to other form of r'esses. l I The press shown consists of a lower frame 1' support ig tiie upper frame"porti0nj2- which carries the driving meanso'f usual form designed at 3Q Thei driving means 3' gives a uniform u'pan'ddown' stroke to'an upper platen 4 which carries'an upper die not shown) Adj Listing mean'sfor' the upper die are generally shown for varying the normal approaeh'of the upper die to the lower die. I 'lh'e upper "platen 4 is guided for a vertical movement by means :comprising side stripse secured to the supporting frame 2 Beneath the upper platen 4 is a lower platen figuided at its ends hy'the supporting frame 2' and adapted to move vertically no response tothe pressurefexerted by the upper side on the materialheld in the lower die The lower cured to the lp ver platen 6. I I platen 6 is snp orted by neans yieldahly resistlng movement of the lower-platenfi until a desired maximum pressure is reached in'the press. Hardened steel blocks are secured at spaced points in accordance with the Width of the press to the lower surface of the platen 6. These blocks'T-have lovver inclined beni- 1g surfaces 8. The, lower part ofthe sup porting frame 1 supports a fixed pressfhele sure because of the ease by whlch air pressure may be var-led and because of the com-:

surfaces 11. Supported to move transversely between'the blocks 7 and 10 is a piston rod 12 guided in the hearing at one side of the I frame 2 and carrying at one end a piston head 13 which slides in a piston cylinder let secured to the side frame portions 1 and 2.

Acylinder head 15 is secured to the cylinder head ltan'd is provided with an opening 16 for the introduction of fluid pressure urging the piston rod 12lOngitudinally. At the end 7 I ofthepiston rod oppositethe piston head is a stop l7which abuts'against the frame'2. 'and'limits the initial movement of the piston rod {12 in one direction. To thepiston'rod' 12 are secured at spaced'points corresponding to the blocks 7 and 10, hardened steel blocks 1 8. Thesev blocks l8 are constructedv to have upper inclined bearing surfaces 19 1 corresponding to the inclines 8 of the block 7 ion the: lower platen (Sand have horizontal lower, bearing surfaces 20 corresponding to the bearing surfaces 11 on the'lower blocks 10. Supported between the bearing surfaces l V8, 19, 11 and 20 of the blocks 7, 10 and 18 are; supported rolling-elements 21 which may, in a preferred form, be rollers. blocks 7, 10 and18 have at each end stop ym'eans 22 holding the rollers 21 in place. A preferred operation of the construction so far described'is as follows: The fluid pressure preferably used to resistniovement of thepiston head 15comprises air pres- V pressibility of the air. The air pressure in the cylinder 1411s regulated in accordance with the maximum pressure desired in the press and initially moves the piston-rod 12 until the stop 17 abuts against the frame.

As the upper platen 4 movesto press the material, the lower platen remains stationary until the desired pressure is reached and then a further,increased'pressure will transmit'through the inclined, surfaces 8 and 19 a horizontalcomponent of force in atrans- I verse direction onthe piston 12 which will be greater than the air pressure resisting" movement, and, therefore, cause a movement of the piston rod and a-corresponding vertical movement of the lower platen 6. P It is apparent 'that the pressure in the cylinder ltwill Vary in accordance with the relative incline of the inclined bearing surfaces 8, 19. Because it is commercially not practicable to attain a high air. pressure,

the horizontal component of the inclines is usually relatively high in relation to the vertical component and may be substantially 100 to 1. Thus a relatively low air presv sure exerted upon the piston rod will result to the movement of the lower platen 6 in.a

relative movement and the piston rod 12 would not be moved in response'to the.pressure on the lower platen 6, therefore, it is necessary to use some means between the bearlng surfaces to diminish the friction,

and, as shown'in the preferred construction, rolling elements,,which may be rollers orv ball bearings, are supported between. the

bearing-surfaces.- V In-the use-of sliding" surfaces the friction increases substantially in proportion to' the pressure upon the surfaces but in the use of rollingelements serving to transmit pressure, the friction remains in asub'stantially constant quantity regardless of, pressure,

therefore, a relatively greater; pressure through the incline bearing: surfaces and exerted in the press will be transmitted i therolling elements and causeairelatively I lowhoriZontal component of pressure upon the piston rod, and, due to theu se of the rolling elements, the .movement of, the pis ton rod will take place asodesired.

By the use of. a press having the improve- V ments described, it is possiblefto develop a uniform pressure upon materialin the 'press regardless of thickness thusinsuring a uniform product, as adjusted to 'a' drawing press there will be a uniform gripping force upon the material. The presses are not so liable to leakage due to excessive pressures and the cushioning action of the air makes for a'quieter operation The distribution of the pressure over a pluralityfof spaced rollers and" a plurality of bearing surfaces permits low bearing pressure upon' individ- V ual elements. Due to the movement of all' -wedges in unison there will be'a" uniform pressure distributed over the lower surface U of the lower platen thus causing perfect parallelism of movement.

I claim:

1. Supporting mechanism for thelower platen of a die press, comprising a trans? versely movable element, blockshaving lower inclined bearmgrsurfaces secured tothe lower surface of the platen, blocks secured V to the transverse movable element having means comprisingrollers held between the inclinedibearlng surfaces.

2.-Supporting mechanism forthe lower upper inclined bearing surfaces, and bearing 5f lower face of'the platen, blocks secured to thetran'sversely movableelement having up per inclined bearing surfaces and lower horizontal bearing surfaces, meanshaving up:

in a greatlyincreased'pressure or resistance per horizontal bearing surfaces beneath the blocks on the transverse element, and rollers held between the respective bearing surfaces.

3. In a press, a'lower' platen vertically movable, an inclined surface-on the lower face of the platen having a small vertical component relative to its horizontal component, a member having a corresponding'ly inclined surface adapted to move transversely relative to the platen, and rolling .ele-

,ments supported between the inclined surfaces serving to transmit to the transversely movable element arelatively small component of horizontal pressure. 1

' 4. A'press, comprising one platen havinga uniform working stroke, a second platen supported to move in response to the move ment of the first platen when the desired working pressure has been reached, means for supporting the second platen comprising a transversely movable element, inclined surfaces on the second platen, andv on the,

transversely movable element, roller bearing elements supportedbetween the inclined surfaces, and means for resisting movement of the transverse element until the desired pressure is reached in the press.

5, Apress comprising one platen having a uniform working stroke, a second platen supported to move in response to the move ment of the first platen when the desired working pressure has'be'en reached, means for supporting the second platen comprising a transversely movable element, inclined surfaces on the second platen, and on the transversely movable element, stop, means limit ing the normal pos1t1on of the transverse element and means for resisting movement of the transverse element until the desired pressure is reached in the press.

'6. A press comprising one platen-having a uniform working stroke, 'a second platen supported to move in response to the movement of the first platen when the desired. I working pressure has been reached, means for supporting the second platen compris ing a transversely movable element, inclined surfaces on the second platen and on, the transversely movable element, rollers supported between the inclined surfaces, means holding the rollers in place on the inclined surfaces and means for resisting movement of the'transverse element until the desired pressure is reached in the press.

7.. A press comprising one platen having a uniform working stroke, a second platen supported to move in response to the movement of the first platen when the desired working pressure has been reached, means for supporting the second platen comprising a transversely movable element, inclined surfaces onthe second platen and on the transversely movable element, roller bearing elements supported between the inclined surfaces and means comprising fluid pressure for resisting -movement1of the transverse in the press} element until the assessme ts is reached, 7

8.]A press corn'prising-oneyplaten having a uniform working stroke, a second platen supported to move -in response to the movement of the first" platen. when the desired working' pressurehas been reached, means i for supporting the second platen compris ing a transversely movable element, inclined surfaces *on "the" second i platen and on the transversely movable element; rollers supfaces, means for holding the rollersiin place on the-inclined surfaces, means limiting the normal position of the transverse element ported between theinclined bearing vsurthe lower platen in a downward direction comprising a rod transversely slidable rela tive to the lowerplaten, inclined wedges secured to the lower platen and rod and I rollers supported between the inclined surfaces.

10. In a press, a press bolster, a lower platen supported above the press bolster and vertically movable, blocks secured to the pressbolster, blocks 'securedto the lower platenhaving inclined surfaces, a piston rod supported to move between the lower platen and the press bolster, blocks secured to the 1 r piston rods having inclined surfaces,'rollers forming bearing means between the inclined surfaces of the blocks on the platen and the piston rod and between the blocks on the press bolster and the blocks on the piston rod, a piston head on the piston rod, a piston cylinder receiving the piston head and air the piston. I V r 11. A press comprising one platen having pressure means for resisting movement of a uniform working stroke, a second platenc movable in response to the movement of the first platen, supporting mechanism for said second platen comprising a transversely movable element, blocks having lower inclined bearing surfaces secured to the loweri face of the platen, blocks secured to the transversely movable element having upper inclined bearing surfaces, and anti-friction I means held between the inclined surfaces.

12. A press comprising one platen hav-l ing a uniform working stroke, a second platen movable in: response tothe movement of the first platen, supporting mechanism for said second platen comprising a transversely movable element, blocks having low-ylto v so and means Comprlslng all pressure fOI' 1'6 er inclined bearing surfaces secured to the lower face of the platen, blocks secured to I the transverselyemovable elemeniarhaving upper inclinedbearing surfaces and lower horiill'inois, this 26th day 

